I think a difference in the exhaust note would distinguish it a bit from the "regular" version, that's it. i don't need it, but i think it's always nice when the different versions also sound a bit different, don't you?
I don't think so, as the S has the standard exhaust and not the akrapovic.
But tbh, i would never pay for the akrapovic, as the difference is there but too small. i would have prefered a cheaper base price and the akrapovic as an option .. but they needed the weight savings for promotion reasons i guess.